Income Taxes - Components of Comprehensive Provision for Income Taxes Allocation (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Schedule Of Income Tax [Line Items]
United States	$ 40.1	$ (70.4)	$ 89.0
Non-U.S. subsidiaries	71.9	(147.5)	212.4
Income (loss) from continuing operations before income taxes	112.0	(217.9)	301.4
Expected tax expense (benefit) at U.S. federal statutory income tax rate of 35%	39.2	(76.3)	105.4
Non-U.S. tax rates	(4.1)	4.3	(11.9)
Incremental tax (benefit) on earnings of non-U.S. and non-tax group companies	(2.2)	(18.5)	1.0
U.S. state income taxes, net	4.1	(3.4)	1.3
Adjustment to the reserve for uncertain tax positions, net	(3.7)	2.1	4.2
Nondeductible expenses	2.8	2.9	4.3
Tax rate changes		(0.2)	1.9
French dividend surtax			0.3
Tax credits	(0.9)	0.1	(2.3)
Other, net	(2.7)	(2.0)	0.6
Provision for income taxes (benefit)	32.5	(91.0)	104.8
Income tax expense (benefit)	32.5	(91.0)	104.8
Income from discontinued operations			5.4
Marketable securities	(11.3)	5.1	(11.6)
Currency translation	(16.9)	5.5	4.9
Total	(30.1)	(65.3)	84.5
Defined Benefit Pension Plans
Schedule Of Income Tax [Line Items]
Defined benefit plans	(33.2)	14.1	(18.3)
OPEB
Schedule Of Income Tax [Line Items]
Defined benefit plans	$ (1.2)	$ 1.0	$ (0.7)